Method of converting spongy lead into lead sulfate.



No. 825,881. PATENTED JULY 17, 1906.

0. J. REED. M EEOD 0E CONVERTING SPONGY LEAD INTO LEAD SULFATE.

APPLICATION FILED MAY'I, 1903.

WITNESSES: INVENTOR W M 6 XQZ /A BY ATTORNEY apparatus and mac UNITED STATES PATENT OFFICE.

CHARLES J. REED, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO SECURITY INVESTMENT COMPANY, A CORPORATION OF PENNSYL- VANIA.

Specification of Letters Patent.

Patented July 17, 1906.

Application flled May 7, 1903. Serial No. 156,098.

To all wham) it may concern.-

Be it known that I, CHARLES J. REED, a citizenof the United States, and a resident of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented a new and useful Improvement in Methods of Convertin Spongy Lead into Lead Sulfate, of which t e following is a specification.

My invention relates to secondary batteries, and particularly to the conversion of the negative-pole electrodes into (positive-pole electrodes electrochemically an without the application of externally-generated electrical energy.

It is a common practice to convert secondary-battery electrodes, which comprise active material in the form of s ongy or finelydivided lead, into positive-polhelectrodes by a reversal process, and this usually consists in cou ling together the plate having the spongy or closed circuit when immersed in dilute sulfuric acid. The electrolytic action which takes place under these conditions converts a large part of the ongy lead into lead suls fate; but it also I'ed l 1c6S\th6 lead'peroxid of the positivepole electrode to lead sulfate, and therefore necessitates the use of a considerable number of'charged positive-pole electrodes, which must subsequently be. re-' charged at a considerable -expenditure of,

electrical energy: ,The, 0 oration also reuires more or less cum rous a paratus, e ectrical machinery and spaceinw ch such for successful operatidn.

My present invention consists in connecting a mass of spongy lead or an electrode containing spongy lead as its active material to an electrodeconsisting of carbon, platinum, or some other metal w 'ch is electronegative to lead and which is ovided; with a coating or deposit of platinum-black or finelydivided platinum and submerg ing such electrodes in a dilute solution of sulfuric acid. By connecting such electrodesinv a closed circuit and submer g them indilute sulfuric acid, as stated, t e electrochemical action .isfexceedingly rapid and the metallic lead is in a short time converted into lead'jsul- In the accompanying drawing I have trated in vertical section 'a' suitable cell or receptacle 1 containingdilute sulfuric acid 2,

ely-divided leadand a perozn'd plate in av may be installed,

.in which are submer ed a late electrode 3, havinga coating of fi nely-divided or spongy' lead, and another plate-electrode 4, havin a coating of platinum-black or finely-di'vi ed platinum, the two plates being connected by a suitable conductor 5. This illustration is merely indicative of suitable means for practicing my process and is not restrictive as re I gards form, dimensions, and relativelocation of parts, except in so far as the process hereinbefore described imposes limitations u on such apparatus. This process not only 0 viates the necessity of em loying'electrical ap-' paratus, and thereby re uces the expense; but it also enables me to convert the spongy lead into lead sulfate thoroughly and expeditiously. a I'claimas my invention 7 s I 1. The rocess of converting spongy or finely-divi ed leadinto lead sulfate,;'which consists in connecting the same in circuit with an electrode having a coating or de osit of platinum-black in a bath of dilute 'snl i uric 2. The process of reversing'taspongy-lead electrode, which consists in'sub ecting the same to the action of dilute sulfuric acidiini V conjunction with ail-electrode having a-coat ing of platinum-black and connected there with in a closed circuit and subsequently charging the same as a perox'id plate.

3. The process of converting the spong" leadv of a negativeole secondary-battery electrode into lead su ate, which consists in subjecting the same to dilute sulfuric acid in comunction'with an electrode ofeleictronegative material having a coating of platinumblack and connected therewith in a closedcir- 4..The process of converting the spongy lead of a ne ative-pole secondary-battery plat'einto lea sulfate which consistsin sub Efiing thesame tolt ewaction' of dilute'sul-- A 0 acid in coniiiuncti ative electrode avinga coating or deposit 'of glatinuimblack or" elyfdivided latmum an to which it is connected in a H V I In tee on-withj an electrone 'o ny I have scribed myname this 23d da of March,,1903.

, SJrREEDp' -Witnesses":M-'

WALTER HJHABT,

', Rename. I 

